Method for controlling items belonging to a commissioning order and a device for carrying out said method

ABSTRACT

Disclosed are a method and an arrangement for checking items ( 3 ) belonging to a commissioning order and transported on a conveyor path ( 1 ) with respect to product type and number of items ( 3 ) by aid of sensing devices ( 10 ) connected with a computer ( 4 ′). Here, each one of the items ( 3 ) is optically or opto-electronically, respectively, checked, optionally after having been individualized and aligned, while being transported.

This is a National Stage entry under 35 U.S.C. §371 of application No.PCT/AT98/00098 filed Apr. 16, 1998, and the complete disclosure of whichis incorporated into this application by reference.

BACKGROUND OF THE INVENTION

The invention relates to a method for checking items belonging to acommissioning order and transported on a conveyor path with respect toproduct type and number of items by aid of sensing devices connectedwith a computer.

Moreover, the invention relates to an arrangement for carrying out themethod.

At present, in large warehouses, items are arranged manually,semiautomatically or automatically to groups of goods according tocommissioning orders and collected in containers. For checking purposes,the containers are guided to weighing devices in the dispatching regionso as to compare the net weight of the container contents with the sumof the individual weights of the items. Since in many instances,particularly in the pharmaceutical whole sale business, productsweighing less than 10 g are in circulation, checks may often yieldincorrect results. A check for the type of product by such a weighingprocedure is hardly possible and also difficult, respectively, sincemany different products have approximately the same weight. Thus, thereis a demand for a control which enables a safe check for the type ofproduct and the number of products.

From DE 691 10 852 D2 a method is known for the commissioning of itemswhich are removed from the compartments of shelves by commissioners byhand, are identified by means of a bar code reading device, weighed, andsubsequently dropped into an empty or already partially filledcontainer. The containers are transported on a main conveyor path so asto be shifted onto one or several secondary conveyor paths which consistof non-driven rollers; adjacent each secondary conveyor path, a manuallydisplaceable checking device is arranged in which identification andweighing of the items are effected by the commissioner. The containersarriving at the checking device are also identified by means of a barcode reading device, and all the data sensed are monitored by a centralcomputer so as to monitor correspondence of the items commissioned inthe containers with the commissioning order; at each checking device, ascreen with a keyboard is additionally provided for interactivecommunication of the commissioner with the central computer. This methodthus provides for a check of the items during the commissioningprocedure itself, the mode of procedure being comparatively complex andstill uncertain.

In EP 572 830 B1 a method of identifying, labelling and targeting ofgoods at the input of goods and/or at the output of goods in a warehouseis described. By “goods”, cartons of equal or different sizes containingitems are to be understood. These cartons pass a checking station inwhich a plausibility check takes place, namely whether or not thepreviously effected identification, weight and volume are in agreement.For identification purposes, a reading device is provided whichpreferably also consists of six scanners to scan the cartons on allsides or to read the information printed on a label; the read actualdata are transmitted to a computer for a comparison with the set data.In this method, however, checking of the items themselves which arecontained in the cartons does not take place so that there, too, thedisadvantages explained above prevail.

SUMMARY OF THE INVENTION

It is thus the object of the invention to provide a method of theinitially defined kind as well as an arrangement for carrying out themethod by which a precise, in particular automatic, checking of theindividual items is carried out while they are being commissioned so asto safely locate faulty groups of goods which do not exactly correspondto a commissioning order.

According to the invention, this object is achieved in the presentmethod in that each item as such is optically or opto-electronicallychecked while being transported. Due to the fact that the individualitems are each separately optically or opto-electronically detected andrecognized, this method allows for a safe checking of the items, andadvantageously it can be employed not only in new commissioninginstallations but also in already existing ones so as to completelyexclude faulty deliveries, which is of particular importance in case ofpharmaceutical products.

With a view to a rapid, automatic and safe checking, it is advantageousif the items are individualized prior to their being checked. Therebythe items can be scanned or “read”, respectively, one after the other.

In this connection it is also advantageous if the items are alignedprior to checking; they may thus be brought into a certain longitudinalor transverse orientation which, although preferred—need not necessarilybe done since there exist multidirectional electronic scanners, e.g.,which can also detect the bar code of non-longitudinally aligned items.

If the items have already been commissioned into containers, accordingto the invention it is of particular advantage for the checking if theitems which have been assembled in a container according to acommissioning order are removed from the container before each of themis checked. Prior to such a check, the items may be individualized andaligned, respectively, as mentioned above. Such a mode of procedureallows groups of items to be put together in the usual manner accordingto the respective commissioning orders and still to be safely checkedautomatically as desired for any mistakes which may have occurred duringcommissioning.

With comparatively poorly identifyable imprints on the items it has alsoproven advantageous if the items are temporarily stopped while beingchecked.

Furthermore, it is suitable if the items, in case of a negative resultof the check, subsequently are corrected respectively in terms of typeand number of products. Subsequently, the item groups initially found tobe incorrect can be delivered immediately so as to comply with thecommissioning order without having to start commissioning anew.

Moreover, it is advantageous if the items of a negative check result canbe removed automatically thus obviating a time-consuming later, inparticular manual, search for the faulty items.

For the rational course of commissioning also during checking it hasfurthermore proven advantageous if the items are transferred into acontainer after having been checked. In this manner, the items whichhave yielded a positive checking result can be passed on immediately asa complete group of goods, e.g. for packing and delivery thereof. Toreduce the number of containers which are in circulation, it is alsosuitable if, after checking, the items are transferred into thatcontainer which originally contained them.

To effectively shorten the checking procedure, it is particularlyadvantageous if several items are checked simultaneously.

In an arrangement for carrying out the method, it is provided that theconveyor path comprises a checking station with automatically operatingoptical or opto-electronical, respectively, sensing devices associatedtherewith or arranged to follow the former. By this arrangement, minimaltime is required as compared with checking carried out by hand, wherebynot only the working time as such with the costs associated therewithcan be saved, but also commissioning orders can be completed even morerapidly—and with certainty.

Advantageously it can also be provided that a container-emptying stationis associated with the conveyor path and that therebehind an aligningand individualizing station is arranged which is followed by thechecking station. By this arrangement, the items can be suitablyprepared for the checking procedure proper by being individualized andlongitudinally aligned so that misreadings by the sensing devices areexcluded. Checking of the individual items themselves on the other handgives a practically 100% certainty of the check for the correctness ofthe assembled groups of goods.

A preferred, advantageous embodiment consists in that the checkingstation comprises a chute formed at least partially of transparentmaterial, at which the optical or opto-electronical sensing devices arearranged transversely to its longitudinal direction. On the chute whichis downwardly inclined by e.g. 30°, the items move past the sensingdevices without requiring a separate drive, e.g. a vibration drive, or aseparately driven conveyor path therefor whose structure mightconstitute an optical impediment to the recognition procedure.

A particularly advantageous embodiment provides for the chute to have aV-shaped cross-section. In this case it is suitable if the legs of thechute enclose an angle of 90° with each other. In this manner, the itemscome to lie snugly with two of their longitudinal side faces on the twolegs of the V-shaped chute, resulting in ideal conditions for an opticalidentification.

Advantageously it can also be provided for the checking station to beformed by a path of small rollers. Between adjacent rollers, also thelower side of the items can be checked, while the upper side and thelongitudinal side of the items are freely accessible to begin with. Ifthe path of small rollers is arranged to be inclined, this variant doesnot require an additional drive either.

In terms of complete automation, it is furthermore particularlyadvantageous if the checking station is followed by a device forautomatically removing the items.

In tests, it has proven particularly suitable if as the sensing devices,at least two, preferably four, scanners or video cameras are arrangedopposite each other. In this manner, imprints or codes on the items oreven their entire appearance can be compared with stored comparativeinformation so as to determine the correctness of the items in a simpleand absolutely certain manner. It has proven suitable if four scannersor video cameras are arranged opposite each other in pairs.

If due to poorly identifyable imprints on the items misreadings couldoccur while they are being moved, it is suitable if a stopping devicefor the items is arranged in the region of the sensing devices. In thiscase it is particularly advantageous if the stopping device comprises asolenoid. To stop the items, the solenoid need only be operated for ashort time resulting in practically no delay of the passage of theitems.

According to a preferred embodiment of the invention it is provided forthe aligning and individualizing station to be formed by several, e.g.laterally offset conveyor paths conveying the items at different speeds.This arrangement in practice has yielded very good results,individualizing and aligning of the items being effected in a relativelyshort period of time. For an alignment of the items while they are beingindividualized, it is also advantageous if the first conveyor path(s) is(are) provided with directing plates for directing the items to the(respective) consecutive conveyor path. With a view to individualizing,it is suitable if the conveying speeds increase from one respectiveconveyor path to the next conveyor path.

The invention will be further explained by way of preferred exemplaryembodiments to which, however, it shall not be restricted, and withreference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 each show a schematic top view onto an arrangement forcarrying out the method according to the invention;

FIG. 3 shows a part of the arrangement according to FIG. 1 in frontview, partially in cross-section, according to line III—III of FIG. 1 orFIG. 2, respectively;

FIG. 4 shows a part of a further arrangement in side view;

FIG. 5 shows a schematic top view onto an example of a device forautomatically removing items arranged to follow the checking station;and

FIG. 6 is a side view of an embodiment of the chute utilizing spaceconveyors.

In FIG. 1, a conveyor path is denoted by 1, which moves items 3dispensed individually and consecutively by an automat 2 according to acommissioning order to a checking station 4 in which the items 3 arechecked in terms of product type and number. Before the items 3 reachthe checking station 4, they are directed to the middle of the conveyorpath 1 by directing plates 5, 6 so as to fall on a chute 7 which isinclined downwardly in transportation direction by 30°, the chute havinga V-shaped cross-section, as is visible in FIG. 3. The directing plates5, 6 may be omitted if the chute 7 and the conveyor path 1 have equalwidths.

The chute 7 is at least partially comprised of a transparent material,preferably glas or transparent plastics, and its legs 8, 9 enclose anangle of 90° so that two longitudinal side faces of the cuboid items 3can lie snugly thereon. Approximately in the longitudinal middle of thechute 7, sensing devices 10, e.g. four scanners, in particular bar codescanners, e.g. multidirectional bar code scanners, which can also sensetransversely arranged bar codes, are arranged transversely to thelongitudinal direction of the chute, or four video cameras 11 a to 11 b(cf. also FIG. 3), whose optical axes are oriented perpendicularly tothe legs 8, 9 or to the four longitudinal side faces of the items 3,respectively. In this manner, either a bar code, a mark, an insript, afigure on the longitudinal side faces and/or the contour of the items 3can be detected optically and transformed into electric signals whichare transmitted to a computer 4′. In this connection it may be providedthat always only one of the items 3 is sensed—from certain sides or fromall sides—, however, if the video cameras 11 or the scanning devices(e.g. several scanning devices adjacently arranged on one level) aresuitable therefor, also simultaneous seinsing of several items can becarried out; what is essential is that each one of the items 3 issensed. By aid of a bar code or sign or picture recognition programstored in the computer 4′, which optionally is also suitable forsimultaneously recognizing several items, both the product type and thenumber of items 3 can be checked thereby and compared with acommissioning order. The result may be displayed for the operatingpersonnel on a screen 12 arranged in the region of the chute 7.

From the chute 7, the items 3 drop into a container 13 which istransported on a conveyor path 14 and stopped at the chute 7.

If the computer 4-determined result of the check regarding the type ofproduct and number of items 3 is in agreement with the commissioningorder, the container 13 is passed on via the conveyor path 14 to adelivery or packing station (not illustrated). If there is no agreement,the container 13′ is transferred outwardly to an area of deposit 15, andthe operating personnel can correct the contents of the container 13′ onthe basis of the data displayed on the screen 12 and optionally transmitthe correction effected to the computer via a keyboard (notillustrated).

In the exemplary embodiment illustrated in FIG. 2, the containers 16filled with items 3 according to a commissioning order reach acontainer-emptying station 18 via a conveyor path 17, e.g. a rollerconveyor path or a conveyor belt, at which the containers 16 are stoppedand are tilted either manually or, preferably, automatically, e.g. via atilting ledge or by aid of gripping means etc. (not illustrated indetail), generally by means of a tilting device 19, to empty theircontents, i.e. the items 3, onto a conveyor path of an aligning andindividualizing station 20. The tilting device 19 illustrated indot-and-dash lines lifts the respective container 16, e.g. at the rearbottom edge, and tilts it over the front bottom edge; the tilting device19 may also lift the container 16 at its collar, transport it to theconsecutive aligning and individualizing station 20 and tilt it there.

In the example illustrated, the aligning and individualizing station 20consists of three laterally offset conveyor paths 21, 22 and 23, theirconveying speeds V1, V2, V3 increasing from the foremost conveyor path21 onto which the items 3 are emptied from the containers 16 up to thelast conveyor path 23, the items 3 at the end of the foremost and middleconveyor paths 21, 22 each being detoured by directing plates 24, 25 tothe consecutive conveyor path 22, 23. Preferably, the second conveyingspeed V2 is twice as high as the first conveying speed V1, and is thethird conveying speed V3 in turn twice as high as the second conveyingspeed V2. By this, a rapid longitudinal alignment of the items in themanner of an “entrainment” and individualization of the items 3 can beachieved.

It is, of course, also possible to carry out individualization of theitems 3 on conveyor paths which are consecutively aligned in one lineand each have a higher conveying speed, wherein optionally alsofunnel-like arranged directing plates may help in the individualizingprocedure.

Alignment and individualizing of the items 3 in the aligning andindividualizing station 20 could furthermore be effected manually,particularly on a relatively slowly moving conveyor path (notillustrated); it may also be completely omitted, if respective sensingdevices 10 are provided which are able to sense several items in randompositions on the basis of their contours as well as imprints; in thisinstance, the sensing devices 10 must have the entire width of theconveyor path in their “field of vision”.

According to FIG. 2, the aligning and individualizing station 20 againis followed by the checking station 4 including the sensing devices 10whose construction and mode of function have already been describedbefore by way of FIGS. 1 and 3, thus obviating any further description.

From the chute 7 of the checking station 4, the items 3 again drop intothe container 16 which in the meantime has been manually or, preferably,automatically taken from the emptying station 18 and put onto theconveyor path 26, and moved to the chute 7, e.g. by means of the tiltingdevice 19 correspondingly designed for transverse displacement, or by aseparate transverse displacement device, e.g. with a pneumaticallyactuated slide (not illustrated), and has been stopped at the chute 7.(A tilting device 19 which could be employed here is, e.g., the oneaccording to DE 30 45 145 A1).

If the computer 4′-determined result of the check regarding the type ofproduct and number of items 3 is in agreement with the commissioningorder, the container 16 with the items 3 is then passed on via aconveyor path 26′ to a delivery or packing station, respectively (notillustrated). If there is no agreement, the container 16′ is againtransferred outwardly to an area of deposit 15, and the operatingpersonnel may again correct the contents of the container 16′ on thebasis of the data indicated on the screen 12 and optionally transmit thecorrection effected to the computer 4′ via a keyboard (not illustrated).

FIG. 4 illustrates a variant of a checking station 4 comprising amodified “chute” 7′ in the form of an inclined path 27 of small rollers.The sensing devices 10 comprise two oppositely arranged (bar code)scanners or video cameras 11′b, 11′c with optical axes extending betweentwo of the small rollers 27 a of the path 27 of small rollers. Moreover,two scanners or video cameras 11′a, 11′d having horizontal optical axesmay be provided, as has been indicated in FIG. 4 in broken lines. Itshould be mentioned here that also in the exemplary embodiment accordingto FIG. 3, only two (or three) bar code scanners or video cameras couldbe employed instead of four bar code scanners or video cameras 11 a-11d.

Laterally of the path 27 of small rollers and for guiding the items 3longitudinally, according to FIG. 4 directing plates 28 are arranged,preferably of transparent material. To allow for an exact reading oroptical recognition in the resting state of the items 3, here also astopping device 29 is provided which is, e.g., formed by a solenoid 30having a plunger core 31 which extends to between two neighboring smallrollers 27 a following the sensing devices 10. The solenoid 30 isexcited for a short time, e.g., by the signal of a photoelectric barrier(not illustrated), so that the passage of the items 3 is only slightlydelayed.

Instead of chutes 7, 7′, also two conveyor belts (not illustrated) maybe arranged consecutively, a sufficiently wide gap being left clear atthe site of transition between the two conveyor belts so as to allow foran optical scanning of the items through this gap.

In the two exemplary embodiments according to FIGS. 1 and 2, also adevice 32 illustrated in FIG. 5 for outwardly transferring thoseindividual items 3 which have given rise to a negative checking resultmay be arranged downstream of the checking station 4 or of the chute 7,7′, respectively. This device 32 is, e.g., a chute 33 following upon thechute 7, 7′, and provided with a pivot arm 34 to be actuatedelectrically via the computer or pneumatically, which pivot armlaterally detours the items 3 found to be incorrect, towards the edge ofthe chute 33 so that they then will drop into a container 35 providedthere. Instead of the pivot arm 34, also a drop flap (not illustrated)may be provided.

Items 3 which have given rise to a positive checking result, on theother hand reach their conveyor path either directly via chute 33, orthey get into a container 13 or 16, respectively, on the conveyor path14 or 26′, respectively, so as to be directed towards the delivery orpacking station, respectively.

What is claimed is:
 1. A conveyor system for transporting items along apath and at least two optical reading devices for checking items withrespect to product type and number disposed in a plane transverse tosaid path on opposite sides of the conveyor system wherein said conveyorsystem has a portion aligned with said reading devices permittingpassage of light therethrough to check the bar code, a mark, aninscript, a figure on the items and/or the contour of the items.
 2. Aconveyor system as set forth in claim 1 further comprising acontainer-emptying station followed by an aligning and individualizingstation prior to the portion aligned with said reading devices.
 3. Aconveyor system as set forth in claim 2 wherein the aligning andindividualizing station is comprised of a plurality of laterally offsetconveyor belts for conveying the items at different speeds.
 4. Aconveyor system as set forth in claim 3 wherein the conveyor belts withthe exception of a last conveyor belt are provided with directing platesfor directing items to the next conveyor belt.
 5. A conveyor system asset forth in claim 3 wherein the conveying speeds increase from eachconveyor belt to a subsequent conveyor belt.
 6. A conveyor system as setforth in claim 1 wherein the portion of the conveyor system aligned withsaid reading devices is comprised of a partially transparent chutehaving a v-shaped cross section.
 7. A conveyor system as set forth inclaim 6 wherein the partially transparent chute is comprised of legswhich enclose an angle of 90° with each other.
 8. A conveyor system asset forth in claim 1 wherein said reading devices are followed by adevice for automatically transferring the items outwardly.
 9. A conveyorsystem as set forth in claim 1 wherein said at least two optical readingdevices are arranged opposite each other.
 10. A conveyor system as setforth in claim 9 wherein four optical reading devices are provided andarranged opposite each other in pairs.
 11. A conveyor system as setforth in claim 1 further comprising a stopping device for stopping theitems, wherein the stopping device is arranged in the region of theoptical reading devices.
 12. A conveyor system as set forth in claim 11wherein the stopping device is comprised of a solenoid.